On the US-Mexico border, loved ones on both sides can see each other but cannot touch

‘How many years has it been since we have seen each other?’

At Friendship Park, the westernmost point of the US-Mexico border, just south of San Diego, US Border Patrol agents help to facilitate and monitor weekend reunions between families separated by the massive barrier – and, by extension, by US immigration policies. Mexicans and Americans have met in the area since the Mexican-American War ended in 1848, and the border was redrawn, significantly favouring the US. Friends and families were able to touch one another through the fence before metallic mesh was added in 2011 for security. With quiet compassion, Monument | Monumento captures several of these unconventional and frequently tearful family reunions, some of which have been decades in the making.

Far from sluggish: the remarkable sea creature that weaponises its dinner

Nudibranchs, also commonly known as sea slugs, are a group of snail-like sea invertebrates. Despite appearing more or less defenceless, nudibranchs broadcast their whereabouts with their flamboyant, brightly coloured bodies. From an evolutionary standpoint, it might seem like a curious move, but their luminous skin actually serves as a warning to would-be predators to let them know they’d make for a dangerous meal. While some nudibranchs accumulate toxins and other defensive chemicals in their bodies, others – like the star of this film – have an even craftier method of warding off enemies. This remarkable short from the science and nature documentary series Deep Look details the clever way that some nudibranchs protect themselves by stealing defences from stinging sea animals known as hydroids. You can read more about this video at KQED Science.

‘My God! Where’s the human voice?’ A charming reflection on our pre-recorded world

From to Siri to subways to customer service calls, pre-recorded and robotic voices are becoming an increasingly inescapable part of the human experience. In this short animation from StoryCorps, the US author, historian and broadcaster Studs Terkel (1912–2008) reflects on this trend away from human interaction and toward disembodied sentence fragments. Recalling a scene from a tram ride at Atlanta airport with exceeding wit and charm, he considers the richness of the human voice, and what we lose when it’s replaced.

From canoes to cities, a frenetic celebration of the power of indigenous Canadians

In her short film Mobilize, Caroline Monnet – a Canadian filmmaker and artist of French and Algonquin origin – uses archival documentary footage to honour the restless diligence of Canada’s indigenous people. Given access to more than 700 films from the National Film Board of Canada for the project, Monnet crafts a fervent visual collage that spans the country’s rural north, where indigenous craftsmen are seen fashioning canoes, to scenes from skyscraper construction in the urban south. According to Monnet, in making the film, she sought to explore the trajectory of her own family’s history, as well as to simply bombard viewers with ‘images of indigenous people kicking ass on screen’. Heightened by a feverish score from the Inuk artist Tanya Tagaq, Monnet’s film offers a deeply original and personal perspective on the indigenous Canadian experience.

This clever and stylish 1960 film is the most fun you’ll ever have at a physics lecture

Directed by the pioneering UK documentarian Richard Leacock, Frames of Reference is a slick and surreal dive into physics fundamentals and, in particular, why everything is indeed relative. Produced for high-school physics classes, the 1960 film features the physics professors Patterson Hume and Donald Ivey of the University of Toronto explaining, through an intertwined series of lectures and clever demonstrations, how frames of reference shape perspective. Using rotating sets, camera tricks and a visual style that suggests the film noir of Alfred Hitchcock, this is perhaps the most peculiarly entertaining half-hour physics lecture you’ll ever have.